USPSA open shooters run 9mm major power factor loads approaching .357 velocities out of 5" barrels. They don't get quite there in the energy department though, but the velocities are getting close with 124 and 115 grain bullets.
I don't think you'll have to do anything special at all with a .357 Sig platform carbine and a slow enough powder to utilize the extra barrel length. You'll make a decent increase over pistol length barrels, the question is whether you can get enough powder in the case to use that extra barrel length. I'd think a 10mm carbine would make a fine gun for deer or bear in the brush with an appropriate load and even at factory pressures.
I don't think you'll have to do anything special at all with a .357 Sig platform carbine and a slow enough powder to utilize the extra barrel length. You'll make a decent increase over pistol length barrels, the question is whether you can get enough powder in the case to use that extra barrel length. I'd think a 10mm carbine would make a fine gun for deer or bear in the brush with an appropriate load and even at factory pressures.